1. Field of the Invention
The present invention is directed toward an apparatus for efficient, durable, reliable, and cost-effective fluid injection. In particular, the present invention provides an unpowered device for automatic fluid injection dictated by pressure differential in the line. More specifically, the present invention provides a device for injecting a degreasing chemical into air relief valves in municipal wastewater systems.
2. Background Information
The ability to manipulate and control the flow of wastewater is a fundamental element in the infrastructure of any civilized society. Modem, municipal wastewater systems are typically designed to take advantage of the force of gravity to control the flow of the wastewater. This, of course, is accomplished by arranging the layout of the hydraulic infrastructure to flow in a downhill direction as much as possible. This system is extremely energy efficient and works well for the most part; however, in many instances, the terrain or other barriers require the direction of flow to be manipulated by a mechanical device. These pumping facilities, or lift stations, are thus required to pump the flow of the sewage over the high spots in the line of the sewage flow, in order to ensure the flow reaches the final treatment plant. Therefore, it is essential to the working structure of any wastewater system to not only have efficient and reliable lift stations, but it is also essential to have reliable pressure lines, or force mains, which carry the wastewater under pressure on its journey to the final treatment plant.
In order to properly protect these wastewater systems from air entrapment and surge (or water hammer), air relief valves must be installed at the “high” points in the sewage force mains. In essence, one requirement for air relief valves in the force main is to allow for release of air or gasses in the lines to prevent pressure build-up. Additionally, air or gasses must be released from the lines in order to reduce the surge, or water hammer, that results from the opening or closing of valves or pumping units throughout the system. However, not only must the air valves reliably open, in order to allow for release of air or gas pressure build-up in the lines, they must also reliably close, in order to prevent contamination of the surrounding areas, and water table in particular, due to the release of sewage through an air valve stuck in the open position.
Clearly, then, these air valves must reliably operate in all conceivable conditions, from urban settings to extremely remote areas, in order to both protect the force mains from over-pressure and water hammer, and to protect the environment from contamination from escaping wastewater. A number of conditions and environmental contributors can effect the reliable operation of such an air relief valve. One such condition is the collection of grease in the sewage lines at the high points of the force mains. Grease from the sewage collects at these points, and inhibits the operation of the air valves, particularly the opening of the air valves in order to prevent overpressure and surge in the sewage lines.
However, although the existence of degreasing chemicals are known in the art to deal with the buildup of grease, no reliable method of introducing the degreaser into the appropriate areas exists, to ensure reliable operation of the air valves. One reason for this lack of technology is the lack of widespread recognition in the art that grease is the culprit to the failure of these air relief valves. Another reason for the lack of development of a reliable, universal system that can be used anywhere in the sewage line for degreasing an air valve, is the fact that often times the remote locations of the air relief valves do not facilitate the use of an electronic or other powered means of actuation and control.
In view of the limitations of products currently known in the art, a tremendous need exists for an automatic fluid injection device that is efficient, durable, reliable, and cost-effective. Applicant's invention, by its novel design provides a solution in view of currently available devices.